Preparation of triarylguanidines



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Patent ed Mar. 13, 1928.

UNETED STATES ram oar-ice.

ALFRED E. PARMELEE, OI C ARNEYS POINT, NEW JERSEY, ASSIGNOR To E. I. DU FONT DE NEMOURS & COMPANY, OF WILMINGTON, DELAWARE, A COBPOBATION OF DELAWARE.

This invention relates to a new process of preparing triarylguanidines, and more particularly to one in which a halogenated hydrocarbon is used asasolvent medium.-

In prior processes of manufacturing such compounds a solvent such ,as alcohol has been used, and more recently an inert solvent such as the hydrocarbon toluene which c. c. aniline.

trative. merely and not definitive.

is immiscible with water, has been used in such a manner as to reflux the solvent while continuously removing the water formed during the operation.

I have discovered that a cleaner separation of the triarylguanidine, and a purer product can be-obtained by using a halogen-= ated hydrocarbon,particularly a low freezing halogen derivatlve of an aromatic hydrocarbon.

As a preferred embodiment of the invention the following procedure will be iven,

bath. The flask is heated until the chlororeflux until it is free from water.

84.4 g. basic lead carbonate are slowly intro benzene boils, whereupon it is allowed to Then duced, and the mass is further heated and refluxpermitted 'to'continue until no more water is evolved. This marks the comple-.

tion of the reaction. The hot mass is then filtered and the lead sulfide sludge is washed with hot chlorobenzene. The combined tiltrate and washings are evaporated to a'small volume. -On cooling'th'e triphenylguanidine separates from solution and is filtered oil and Washed once with cold chlorobenzene.

The isolated triphenylguanidine is pure white, and analysis? shows it to be 99% pure. whereas the Its meltingpoint is '146' C.

The yield is literature gives it as 144.5 C. 90% of the theoretical yield.

In a similar way may bon solvent.

I PREPARATION TRIARYLGUANIDINE S.

Application filed April 9, 19284. Serial No. 705,210.

be prepared from diaryl thioureas and aryl amines, by the aid of a desulfurizing agent, in the presence of a halogenated hydrocar- In the above given example, the 'trlphenylguanidine, aniline, and thiocarbanilide are soluble in the chlorobenzene, while the latter is insoluble in water. Substituted and otherwise modified .products may be similarly prepared. Halogen derivatives of hydrocarbons having freezing points of about C. or lower, and boiling points above 100 C. are especially suitable for use in the present process.

As many apparently widely different enibodiments of this invention may be made without departing from the spirit thereof", it is to be understood that I do not intend to limit myself to the specific embodiments thereof except as indicated in the appended claims.

I claim: 1 1. The process of making a triarylguanidine, which comprises treatin a diaryl thioure'a with an aryl. amine and a desulfurizing agent in the presence of a chlorobenzene.

2. The recess of making a triarylguanidine, which comprises treatin a diaryl thiourea with anaryl amine an a desulfurizing agent in the .presence of chlorobenzene; distilling and refluxing said halogenated hydrocarbon, and removing water therefrom.

3. 'The processof making triphenylgnanidine, which comprises treatin thiocarbanilide withaniline'and a desulfin'izing agent in the presence of chlorobenzene.

4. The process of making triphenylguanidine, which comprises treating thiocarban1- lide with aniline and-a desulfurizing agent in the presence of chlorobenzene, distilling and refluxing said halogenated hydrocarbon, and removing Water therefrom.

5. The process of making triphenylguanidine. which com rises heatin thiocarbanilide, aniline, and asic lead car nate in the presence of chlorobenzene. I

In testimony whereof I afiix my signature.

ALFRED E. PABMELEE. 

